Messages in this thread | | | From | Tomasz Figa <> | Subject | Re: [PATCH v2] watchdog: s3c2410_wdt: Only register for cpufreq on ARM_S3C24XX_CPUFREQ | Date | Tue, 26 Nov 2013 01:03:49 +0100 |
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On Monday 25 of November 2013 15:36:43 Doug Anderson wrote: > On modern SoCs the watchdog timer is parented on a clock that doesn't > change every time we have a cpufreq change. That means we don't need > to constantly adjust the watchdog timer, so avoid registering for and > dealing with cpufreq transitions unless we've actually got > CONFIG_ARM_S3C24XX_CPUFREQ defined. > > Note that this is more than just an optimization. The s3c2410 > watchdog driver actually pats the watchdog on every CPU frequency > change. On modern systems these happen many times per second (even in > a system where "nothing" is happening). That effectively makes any > userspace watchdog program useless (the watchdog is constantly patted > by the kernel). If we need ARM_S3C24XX_CPUFREQ defined on a > multiplatform kernel we'll need to make sure that kernel supports > common clock and change this to user common clock framework. > > Signed-off-by: Doug Anderson <dianders@chromium.org> > --- > Changes in v2: > - Use the updated config name. > > drivers/watchdog/s3c2410_wdt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Best regards, Tomasz
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